5"/25 caliber gun
bore (25 calibers) 8 ft 2 in (2.4 m) rifling |width= |height= |crew= |cartridge= United States of America 5"/25 (12.7 cm) Marks 10, 11, 13 and 17 |caliber= |action= |rate= |velocity= 2,100 ft/s (640 m/s) average |range= |max_range= |feed= |sights= |breech= |recoil= |carriage= |elevation= to +85° |traverse= |diameter= |filling= |filling_weight= |detonation= |yield= }} The 5"/25 caliber gun (spoken "five-inch-twenty-five-caliber") entered service as the standard heavy anti-aircraft (AA) gun for United States Washington Naval Treaty cruisers commissioned in the 1920s and 1930s. The goal of the 5"/25 design was to produce a heavy AA gun that was light enough to be rapidly trained manually The gun was also mounted on pre-World War II battleships and aircraft carriers until replaced by the standard dual-purpose 5"/38 caliber gun, which was derived from the 5"/25 and was similar except for the barrel length.Campbell 1985 p.137 United States naval gun terminology indicates the gun fired a projectile 5 inches (127 mm) in diameter, and the barrel was 25 calibers long (that is, for a 5" bore and a barrel length of 25 calibers, 5" x 25 = 125", or about 3.2 meters).Fairfield 1921 p.156 History 's 5"/25 battery prepares to fire during the bombardment of Saipan, 15 June 1944]] The gun weighed about 2 metric tons and used fixed ammunition (case and projectile handled as a single assembled unit) with a 9.6-pound (4.4 kg) charge of smokeless powder to give a 54-pound (24 kg) projectile a velocity of 2100 feet per second (640 m/s). Ceiling was at the maximum elevation of 85 degrees. Useful life expectancy was 4260 effective full charges (EFC) per barrel. The short barrel of the 5"/25 made it much easier to train manually against fast-moving targets. These guns were manually controlled so the short barrel and light weight made it an early favorite as an anti-aircraft gun. Another key feature was power loading, allowing rapid fire at high elevation angles. The 5"/38 caliber gun replaced the 5"/25 as the anti-aircraft weapon of choice on new construction by the mid-1930s due to its better range, velocity against surface targets, and higher vertical ceiling. 5"/25 guns removed from pre-war battleships (especially those rebuilt after Pearl Harbor) had their barrel linings chromed. These guns then began being mounted on submarines in late 1943 for extra firepower against small boats and sampans often encountered off the coast of Japan and elsewhere in the Pacific Theater, replacing the earlier 3-inch and 4-inch guns. The Mark 17 gun in the Mark 40 submarine gun mount used semi-fixed ammunition (case and projectile handled separately) and had a range of at the maximum elevation of 40 degrees.Campbell 1985 p.138 The submarine mounting had manual elevation, train, and loading with no power assist. Ships mounting 5"/25 caliber guns * Fahey 1941 p.9 * * * * * * * * * * * * * * * * * * * * * * * * Friedman 1983 p.390 * * Friedman 1983 p.391 * Breyer 1973 p.210 * * Breyer 1973 p.214 * * Breyer 1973 p.219 * * * Breyer 1973 p.226 * * Breyer 1973 p.230 * * *Balao class submarines *Tench class submarines Notes References * * * * * * External links *5-INCH GUN MOUNT MARK 40, OP 1029, 1944. Manual for submarine gun & mounting Made available online by Historic Naval Ships Association Category:World War II naval weapons Category:Naval guns of the United States Category:127 mm artillery Category:Naval anti-aircraft guns